For many years there has been a desire to develop various types of lockable caps or closures for containers that will hold substances that might be harmful or poisonous or various types of medications to which access should be controlled especially if accessible to children.
Exemplary of this type of device is the closure shown in Towns, U.S. Pat. No. 2,964,207. The two types of caps disclosed in this patent are comprised of two parts that are irremovably connected together in a manner that permits relative rotation so that when the sides of the outer member are squeezed inwardly or when the top is pushed downwardly, the two members are joined together to permit simultaneous rotation. When they can rotate simultaneously, then the closure can be either placed on or removed from the container.
Other types of lockable closures have required the use of a key or some other type of exterior release device to open them and exemplary of these closures are those shown in Cumming, U.S. Pat. No. 824,913; Oberle, U.S. Pat. No. 2,820,565 and Glick, U.S. Pat. No. 3,973,687. Each requires use of a key to release a locking device located internally within the closure or within the bottle stopper as in Cumming.
Various uses of magnetic type release devices have also been a subject of U.S. patents. Specifically, Flower, U.S. Pat. No. 3,060,786, relates to a type of connecting nut having a magnetically operated driving means. The nut itself is used to drive a clutch mechanism that is normally out of engagement with drive lugs. The clutch member is comprised of a ferromagnetic material and when a magnet is applied the clutch member is pulled downwardly against the spring and onto the drive lugs allowing the thus engaged drive means to be operated.
Eyster et al, U.S. Pat. No. 4,223,799, also relates to a releasable locking means for closure caps, primarily for fill pipes used on tanks. The cap includes a ferrous material internal locking device which can move a limited distance vertically within the cap. The locking member operates by gravity when no magnet is being applied and as long as the container or tank is upright, the locked device will normally be in its down and locked position. The locking device is comprised of a central cylindrical section having an hexagonal head member at one end of that section and a transversely extending locking pin or bar at the opposite end. This transverse locking pin is designed to cooperate with an inwardly extending annular flange within the fill neck of the container or tank and a series of pairs of diametrically opposed recesses are provided within that annular flange. When the locking device is in its down position due to gravity, the transverse locking pin will fit within one of those pairs of diametrically opposed recesses and prevent rotation of the cap. The subsequent application of a magnet on the exterior of the closure will raise the locking device and, likewise, the pin out from the recesses. Of course, if the container were inverted the locking device would, through gravity, also move out of its locked position and allow closure removal.
Alternatively, the locking device can be comprised of a cylindrical member having a pair of diametrically opposed slots, each of which fit around a pin within the intake tube on which the cap is placed. Alternatively, the locking device can be comprised of a pair of pins, but it can also extend over and engage between them the horizontally extending pin extending radially inwardly from the side wall of the container's inlet. When the container is upright, unlocking is again accomplished by an exteriorly applied magnet. In still another embodiment, the locking device is in the form of a hexagonally shaped cap member that again can slide vertically within the cover with the bottom portion of that cap member being provided with tabs that fit into a flange device in which diametrically opposed pairs of recesses have been provided.
In Montgomery et al, U.S. Pat. No. 2,090,302, a dummy-type fuse is disclosed and in one embodiment, a ferromagnetic arm having a sharpened end is provided within the fuse. A spring forces the sharpened end into contact with the shell of the fuse socket preventing the dummy fuse from being unscrewed. When a magnet is applied to the exterior of the dummy fuse, the arm is pivoted toward the magnet, against the force of the spring, and away from the shell. This releases the sharpened end from against the shell of the fuse socket and allows removal of the dummy fuse. In another series of embodiments, two ferromagnetic cylindrical pellets are provided within a recess between an outer and inner portion of the dummy fuse which are rotatable one relatively to the other. When no magnetic force is applied either externally or internally, the two cylindrical pellets meet at the interface between the inner and outer members and permits the outer member to be rotated freely with respect to the inner member so that the fuse plug cannot be removed. Upon the application of magnet, either from the exterior or from the interior, the two cylindrical pellets are moved so that the lower pellet is positioned across the juncture between the inner and outer portions. This prevents their relative rotation and allows the dummy fuse to either be removed from or placed in the fuse plug opening.
In Berducone, U.S. Pat. No. 3,744,833, a magnetic latch is disclosed. The latch is comprised of a pair of magnets, one fixed and one that is vertically slidable. The two magnets are positioned to be in a mutual repelling relationship so that the slidable magnet is urged into a latching position. Upon the application of a third magnet from the exterior of the latch, the repelling force of the interior magnet is overcome and the slidable latching magnet is moved from its latching position which allows the top of the container to be opened.
It was found that many of the safety designed tops presently being used and available, are in fact child resistant but at the same time extremely difficult for the elderly or people suffering from arthritic problems in their hands to open such closures. This is because many of the child-resistant tops depend upon hand or finger strength or a certain amount of dexterity of the opener's hands. In other words, something other than merely gripping the closure is required.
In addition, it has been noted that closure devices that rely on gravity, such as in Eyster et al, U.S. Pat. No. 4,223,799, do not provide the needed lockability since when containers are oriented in a direction other than that which would produce locking, the container could be easily opened.
Thus, the present invention is designed so that the device is not orientation limited, that is that gravity does not affect its operation even when the container is inverted. Similarly, it was desired to develop a closure device that would only require gripping of a sufficient amount to unscrew the closure rather than to also overcome the effects of a child-resistant mechanism.